The embryonic nucleologenesis during inhibition of major transcriptional activity in bovine preimplantation embryos

TY - JOUR

T1 - The embryonic nucleologenesis during inhibition of major transcriptional activity in bovine preimplantation embryos

AU - Kovalská, Mária

AU - Hruška-Plocháň, Marián

AU - Østrup, Olga

AU - Adamkov, Marian

AU - Lehotský, Ján

AU - Strejček, František

AU - Statelová, Dagmar

AU - Mikušková, Katarína

AU - Varga, Ivan

AU - Petrovičová, Ida

PY - 2012/8

Y1 - 2012/8

N2 - Common features of embryonic genome activation in mammalian and non-mammalian embryos are the colocalization of pre-assembled complexes of maternally inherited nucleolar proteins, the so-called nucleolus precursor bodies and de novo synthesized transcripts with ribosomal DNA. The de novo transcription of messenger RNA and ribosomal RNA proteins is required for the development of functional nuclei during the major activation of the embryonic genome. The aim of our work was to investigate to what extent. Autoradiography and transmission electron microscopy has been applied in in vitro produced bovine embryos. The embryos were cultured to the late 8-cell stage with: α-amanitin; a specific inhibitor of RNA-polymerases II and III transcription; actinomycin D; a specific inhibitor of RNA polymerase I transcription; and without inhibitors (control group). Nucleoplasm and nucleolar structures displayed strong autoradiographic labeling and showed the initial development of fibrillo-granular nucleoli in the control group. In α-amanitin groups, however, in both inhibited groups of embryos, lack of autoradiographic labeling and disintegrated nucleolus precursor bodies stage were observed. Our study of α-amanitin as well as in actinomycin D groups proves inhibition of transformation nucleolus precursor bodies to active nucleoli. From our results follows, actinomycin D is able to penetrate through zona pellucida, what was shown for the first time.

AB - Common features of embryonic genome activation in mammalian and non-mammalian embryos are the colocalization of pre-assembled complexes of maternally inherited nucleolar proteins, the so-called nucleolus precursor bodies and de novo synthesized transcripts with ribosomal DNA. The de novo transcription of messenger RNA and ribosomal RNA proteins is required for the development of functional nuclei during the major activation of the embryonic genome. The aim of our work was to investigate to what extent. Autoradiography and transmission electron microscopy has been applied in in vitro produced bovine embryos. The embryos were cultured to the late 8-cell stage with: α-amanitin; a specific inhibitor of RNA-polymerases II and III transcription; actinomycin D; a specific inhibitor of RNA polymerase I transcription; and without inhibitors (control group). Nucleoplasm and nucleolar structures displayed strong autoradiographic labeling and showed the initial development of fibrillo-granular nucleoli in the control group. In α-amanitin groups, however, in both inhibited groups of embryos, lack of autoradiographic labeling and disintegrated nucleolus precursor bodies stage were observed. Our study of α-amanitin as well as in actinomycin D groups proves inhibition of transformation nucleolus precursor bodies to active nucleoli. From our results follows, actinomycin D is able to penetrate through zona pellucida, what was shown for the first time.

U2 - 10.2478/s11756-012-0066-1

DO - 10.2478/s11756-012-0066-1

M3 - Journal article

SN - 0006-3088

VL - 67

SP - 818

EP - 825

JO - Biologia

JF - Biologia

IS - 4

ER -